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Franz Franz

goFranz // personal journal
Senior Identity Engineer · Verifiable credentials · AI for regulated systems

I build identity and trust systems, and now the AI inside them

Senior Identity Engineer, TWIN (IOTA Foundation) · Independent architect for digital identity and regulated AI

Fourteen years building identity, verifiable-credential and regulated-data systems for healthcare, finance and digital-asset platforms in Europe and Southeast Asia. Current focus: AI inside products where a wrong answer has consequences, kept compliant with the EU AI Act.

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Franz Geffke
Franz Geffke
RoleSenior Identity Engineer @ TWIN (IOTA Foundation)
Based inLisbon, Portugal · Europe, Middle East, Southeast Asia
FocusDigital identity · OID4VP · SD-JWT VC · vLEI · EU AI Act

Latest writing

118 entries · since 2014

Work with me

I take on a few outside engagements a year: identity and systems work, or AI where a wrong answer has consequences. Recently that's meant an OID4VP verifier interop-tested against the official EUDI Reference Wallet, and a GLEIF vLEI to IOTA DID bridge with keys that never leave the browser. Selected work has the rest.

Identity & systemsDigital identity, verifiable credentials, KYC, and the backend around them. TypeScript and Rust, architecture to production.start a conversation → AI building, proofing and trainingAI that fits your stack, EU-resident or self-hosted. Security reviews of what you already shipped, and training for the people who have to run it./work-with-me →

Software

19 projects · open source and SaaS

I also build and maintain open-source and SaaS tools: identity tooling, Rust libraries, a privacy-first AI platform. See Software.

Around the world

Where I've worked

Based in Lisbon, Portugal. Born in East Germany; delivered projects in Thailand, Singapore, Malaysia, the UAE, Iran, Turkey and across Europe. The pins are projects and places.

Selected work

Healthcare

Remote Patient Monitoring System

End-to-end platform (BLE devices, real-time gateway, clinician dashboard) handling regulated patient data for a Thai healthcare provider. Bangkok, Thailand Identity · Mobile

Mobile Authenticator

Strong-authentication app and backend for a Thai digital service: KYC-gated onboarding, OIDC/CIBA, digital signatures. Bangkok, Thailand Digital identity · EU

OID4VP Verifier, EUDI Wallet Interop

OpenID for Verifiable Presentations verifier on the EU HAIP profile, tested against the official EU Digital Identity Reference Wallet. SD-JWT VC presentation and validation. Berlin, Germany Organisational identity · Finance

GLEIF vLEI to IOTA DID Bridge

Organisational identity credentials (KERI/vLEI, the GLEIF trust root for legal entities) bridged to decentralised identifiers on IOTA. Browser-based key management. Berlin, Germany

Tell me what you're building and where it's stuck. I'll tell you quickly whether I'm the right person for it, and if not, who might be.

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